Curevac has reported that the ongoing Phase I study of its Covid-19 vaccine candidate CVnCoV showed that it was well-tolerated across all tested doses ranging from 2 to 12µg and induced strong binding and neutralising antibody responses.
The Phase I study is evaluating the safety, reactogenicity and immunogenicity of the investigational vaccine CVnCoV, an optimised, non-chemically modified mRNA that encodes the prefusion stabilised full-length spike protein of the SARS-CoV-2 virus.
Its mode of action imitates the natural immune response to the Covid-19 infection observed in recovered patients.
The Phase I dose-escalation study has so far enrolled over 250 healthy subjects aged 18 to 60.
Participants were vaccinated intramuscularly with CVnCoV at escalating dose levels of 2µg, 4µg, 6µg, 8µg and 12µg on days one and 29.
For every dose level, the trial had up to ten Covid-19 positive participants to further evaluate the safety and immunogenicity of the vaccine candidate in this sub-population.
Early data from the trial showed indications of functional T cells confirming the activation of cellular immune response, with the analysis of T cell-mediated immunity progressing.
Immunogenicity data demonstrated the induction of binding antibody titers, translating into relevant virus titers, neutralising antibodies at all tested dose levels.
CureVac chief technology officer Dr Mariola Fotin-Mleczek said: “These initial data show a robust and highly efficient immune response to our natural mRNA-based CVnCoV vaccine candidate, including antibody and initial T cell responses at the level of a relevant panel of symptomatic convalescent patients.
“We are grateful to all study volunteers who are helping to enable the development of a vaccine that will provide the best possible protection for people.”
The trial data supports the use of a 12µg dose of CVnCoV for the upcoming Phase IIb/III study.
In September, CureVac initiated the dosing of participants in a Phase IIa trial of CVnCoV. The dose-confirmation study on 690 healthy participants aged 61 or above and those aged 18-60 is progressing in Peru and Panama.